Seismic performance of cable-sliding friction bearing system for isolated bridges   总被引：1，自引：0，他引：1  

Cheung Pakchiu 《地震工程与工程振动(英文版)》2012,11(2):173-183

During past strong earthquakes, highway bridges have sustained severe damage or even collapse due to excessive displacements and/or very large lateral forces. For commonly used isolation bearings with a pure friction sliding surface, seismic forces may be reduced but displacements are often unconstrained. In this paper, an alternative seismic bearing system, called the cable-sliding friction bearing system, is developed by integrating seismic isolation devices with displacement restrainers consisting of cables attached to the upper and lower plates of the bearing. Restoring forces are provided to limit the displacements of the sliding component. Design parameters including the length and stiffness of the cables, friction coefficient, strength of the shear bolt in a fixed-type bearing, and movements under earthquake excitations are discussed. Laboratory testing of a prototype bearing subjected to vertical loads and quasi-static cyclic lateral loads, and corresponding numerical finite element simulation analysis, were carried out. It is shown that the numerical simulation shows good agreement with the experimental force-displacement hysteretic response, indicating the viability of the new bearing system. In addition, practical application of this bearing system to a multi-span bridge in China and its design advantages are discussed.  相似文献   

试论伊犁盆地库捷尔太铀矿床常量元素的活动性   总被引：3，自引：2，他引：1  

王金平闵茂中  彭新建陈跃辉 朱西养 《地质论评》2005,51(2):143-150

传统的对控矿层间氧化带的研究往往偏重于铀及其相应的伴生元素(Se、Mo、V、Re、Ga等)的地球化学行为,而对常量元素中非变价元素如：Si、Al、Na、K等研究还很不充分。事实上,层间氧化作用过程中,随着成矿流体的运移和水一岩反应的进行,介质的物理化学条件如Eh、pH等必然会发生显著的改变,而这些改变或多或少的总会在成矿主岩中最常见的元素如：Si、Al、Fe、Na、K的地球化学行为上显示出来。这种改变首先体现在含有上述元素的矿物上的一系列变化,并最终导致元素含量上的改变。不同的元素在这一过程中具有不同的地球化学行为,按照其迁入迁出的强度,这些元素可以划分为活动组分、次活动组分和惰性组分3类。  相似文献   

塔河油田防漏堵漏技术综述          下载免费PDF全文

王伟志  刘庆来  郭新健  王骁男 《探矿工程》2019,46(3):42-46,50

塔河油田是我国重要的油气产区,井漏的发生对油气的安全生产危害极大。塔河油田的井漏问题会多发生在二叠系、石炭系以及奥陶系层位,原因大致可归纳为：二叠系地层裂缝发育、石炭系地层敏感性高、奥陶系缝洞型地层漏失空间大。本文对塔河油田的地质特点进行总结,对由此而产生的井漏等井下事故问题进行了阐述与分析,总结了塔河地区防漏堵漏的技术方法,对以后该区域的开发利用具有一定的借鉴参考价值。  相似文献   

Imaging-Based Characterization of Perthite in the Upper Triassic Yanchang Formation Tight Sandstone of the Ordos Basin,China     

DU Shuheng  SHI Guoxin  YUE Xinjian  KOU Gen  ZHOU Bo  SHI Yongmin 《《地质学报》英文版》2019,93(2):373-385

This work investigated the element distribution of perthite from the Upper Triassic Yanchang Formation tight sandstone in the Ordos Basin of northern China by field emission scanning electron microscopy(FE-SEM) and energy dispersive spectrometer(EDS). FE-SEM results indicate significant differences in the morphology of Na-rich feldspar when K-rich feldspar is the main component of the perthite. EDS results show that different types of perthite have clearly defined differences on different element indexes. Additionally, indexes such as average-weight-K(K-rich)/Na(Na-rich), maximumweight-K(Na-rich)/Na(Na-rich) and average-atomic-K(K-rich)/Na(Na-rich) might be the most effective ones to identify perthite types. Perthite is divided into six main types, i.e., perthite with thick parallel stripe distribution, with thin parallel stripe distribution, with lumpy stripe distribution, with dendritic stripe distribution, with encircling stripe distribution, and with mixed stripe distribution.  相似文献   

����GPS��InSAR�����봨Mw7.9����ϲ㻬���ֲ�   总被引：1，自引：1，他引：0  

张国宏  屈春燕  汪驰升  宋小刚  张桂芳  单新建 《大地测量与地球动力学》2010,30(4):19-24

??????8.0????????????????????????????????????λ??????????????η????????ν??????????????????8.0??????GPS??InSAR????α??????????????????????????????????????????1?????????????????GPS??InSAR??????????α????????????97.27%;2??????????????????????????????????????0??20 km??????????????λ???????????????????????????????????????????0??20 km???????????????????10 m????????10??15 km?????????????6.5 m??3??????????????????????????????????????????????????????????103??????????????????????121????????????????????138??????????????????????????105??4?????????????????8.7??10 ²⁰ Nm???????Mw7.9??  相似文献   

采用随机计算方式的单片机的电感应变数字测量装置     

唐新建  李楚 《岩土力学》1989,10(1):67-78

本文设计了一种以8031单片机为核心的高分辨电感应变数字测量装置。文中讨论了随机量化问题。计算机的数值计算用随机量化法进行处理,以提高运算精度。在软件设计中,应用了状态法和中断的子程序嵌套方案。试验表明,该装置结构合理,达到了预定的技术要求。  相似文献   

长江下游沿江湿地升金湖越冬水鸟觅食集团结构及生态位特征     

王新建  周立志  陈锦云  范少军 《湖泊科学》2021,33(2):518-528

集团结构和生态位特征是量化动物群落组织过程的重要指标,鸟类集团结构及其食物资源分割的分析对于理解群落中不同鸟种生态适应性具有重要意义.越冬水鸟集团结构和生态位特征取决于食物资源的丰富度和可获得性.本文通过对升金湖越冬水鸟的觅食生境和觅食行为的观察,对水鸟群落的集团结构进行划分,采用Levins指数和Pianka指数计算生态位宽度和生态位重叠度.结果表明,升金湖越冬水鸟可被划分为4个觅食集团,即G1浅水啄食集团、G2草滩啄食集团、G3广食性集团和G4深水潜水觅食集团.在浅水和中水区的觅食集团物种组成比深水区的水鸟集团丰富.G3广食性集团的生态位宽度远高于其余3个特化集团.比较而言,所有水鸟物种的觅食行为均较特化,但在觅食生境方面却较宽化.同一集团内物种间的生态位重叠远高于集团间的生态位重叠.G3广食性集团内物种的生态位重叠度低于其它特化集团内物种的生态位重叠度.研究结果表明,升金湖越冬水鸟群落集团结构主要受食物资源空间配置及其可利用性的影响.水鸟群落结构和生态位特征的信息对监测升金湖湿地的质量和制定有效的湿地保护策略都具有重要意义.  相似文献   

福鼎市冬季坡地低温考察和龙眼、荔枝园地选择   总被引：9，自引：0，他引：9  

蔡文华  林新坚  张辉 《气象》2005,31(9):79-82

据福鼎市2003／2004年度冬季低温考察资料分析,对于一百多米的小山坡,在相对高差约2／3附近的山坡中上部,晴天其最低气温常出现最高,逆温效应最明显,该地段种植龙眼、荔枝可减轻或避免低温造成的冻害。  相似文献   

Ground Surface Ruptures and Near‐Fault,Large‐Scale Displacements Caused by the Wenchuan Ms8.0 Earthquake Derived from Pixel Offset Tracking on Synthetic Aperture Radar Images     

QU Chunyan  SHAN Xinjian  LIU Yunhu  ZHANG Guohong  SONG Xiaogang  ZHANG Guifang  GUO Liming  HAN Yufei 《《地质学报》英文版》2012,86(2):510-519

The 12 May 2008 Wenchuan Ms8.0 earthquake produced surface displacements along the causative fault, the Yingxiu–Beichuan Fault, which are up to several meters near the fault. Because of the large gradient, satellite synthetic aperture radar (SAR) interferometric data are strongly incoherent; the usual SAR interferometry method does not allow such displacements to be measured. In the present study, we employed another approach, the technique based on pixel offset tracking, to solve this problem. The used image data of six tracks are from the Advanced Land Observing Satellite, Phased Array type L-band Synthetic Aperture Radar (ALOS/ PALSAR) dataset of Japan. The results show that the entire surface rupture belt is 238 km long, extending almost linearly in a direction of 42° north–east. It is offset left laterally by a north–west-striking fault at Xiaoyudong, and turns at Gaochuan, where the rupture belt shifts toward the south by 5 km, largely keeping the original trend. In terms of the features of the rupture traces, the rupture belt can be divided into five sections and three types. Among them, the Beichuan–Chaping and Hongkou–Yingxiu sections are relatively complex, with large widths and variable traces along the trend. The Pingtong–Nanba and Qingping–Jingtang sections appear uniform, characterized by straight traces and small widths. West of Yingxiu, the rupture traces are not clear. North of the rupture belt, surface displacements are 2.95 m on average, mostly 2–3.5 m, with 7–9 m the maximum near Beichuan. South of the rupture belt, the average displacement is 1.75 m, dominated by 1–2 m, with 3–4 m at a few sites. In the north, the displacements in the radar line of sight are of subsidence, and in the south, they are uplifted, in accordance with a right-slip motion that moves the northern wall of the fault to the east, and the southern wall to the west, respectively. Along the Guanxian–Jiangyou Fault, there is a uplift zone in the radar line of sight, which is 66 km long, 1.5–6 km wide, and has vertical displacements of approximately 2 m, but no observable rupture traces.  相似文献   

福建浦城管查铜矿床地质特征及找矿前景分析     

占新建 《福建地质》2012,31(4):315-324

浦城管查铜矿位于峡口—古楼北北东向断裂带上,矿体贮存于早元古代麻源群南山组变质岩和晚侏罗世下渡组火山岩中,受北东向断裂构造控制,矿体呈脉状、透镜状产出,为中低温热液充填交代型矿床。  相似文献